RPD2 3

  1. framework try-in app.
    • 1. inspect (consult)
    • 2. seat/fit
    • 3. physiologic adjust (EXTENSION BASE)
    • 4. occlusal adjust
    • 5. altered cast impression (ext base only)
  2. Pressure indicator made from:
    Chloroform and rouge
  3. Do not adjust ________ before consulting with an instructor.
    • retainers
    • adjust framework w/ high speed burs
  4. UCLA functional design classifications
    • 1. tooth borne: abutment tooth borders edentulous, functional forces tranmitted through abutment
    • 2. extension base: distal or anterior extension, force thru abutment & MUCOSA to bone
  5. Differential displacement (PDL vs. Mucosa)
    • PDL: 0.25mm
    • Mucosa: 2.0mm
  6. axis of rotation through:
    • 1. rest closest to extension base
    • 2. farthest rest
  7. physiologic adjusment
    • Provide the RPD framework with physiologic relief to allow for its movement along the axis of rotation
    • masticatory forces vs. proximal plate/minor connector could bind teeth during RPD functional movements
  8. Why physiologically adjust?
    • Establish a safety factor for abutment teeth to minimize the torquing or binding force due to
    • (1) the different compressive capacity of hard and soft support
    • (2) perspective bone resorption
    • Effective preventive measure to protect abutment teeth for long run!
  9. How to physiolgically adjust?
    • The framework is placed in the mouth and moved in
    • hyperfunction by pressing the denture base connector in the extension area
    • Then, grind the high pressure areas.
    • Until the framework moves easily with
    • 1) the rest at the axis of rotation rolling smoothly without lifting,
    • 2) the I-bar moving forward slightly,
    • 3) the abutment not being torqued. Be cautious to over-shave the metal or you will lose the retention and stability.
  10. No more adjustments should be made when the metal reaches ____ mm thickness.
  11. Adjustments are made to the framework (rests and minor connectors) until __________
    • 1. natural teeth are in contact
    • 2. no interference during excursive movements
  12. Altered Cast Procedure
    obtain the maximum support possible from the edentulous area of the extension partial denture
  13. How to fabricate an altered cast tray
    • framework is placed on the master cast.
    • single layer of wax is placed over the edentulous area to provide a space for the impression material.
    • Remove some wax from the denture base connector area
    • to provide for the mechanical index of the tray acrylic to the metal.
    • Lubricate separating medium and apply the tray acrylic
    • The acrylic trays are trimmed and polished
    • Make 2-3mm space for border molding
    • Do not bond to the framework at this point.
    • The altered cast tray is connected to the framework using a thin layer of GC Pattern Resin or DuraLay after the physiologic adjustment is complete
  14. Clinical steps of altered cast impression
    • 1. checked proper peripheral extension in mouth
    • 2. Border molding
    • 3. cut back 1 mm for the impression material
    • 4. Vent holes near the finish line
    • 5. adhesive 2-3 mm exceeding the flange.
    • 6. Mix and load
    • 7. seat in the mouth ensuring COMPLETE SEATING
    • a. rests in the right positions
    • b. necessary movements of soft tissues. H
    • c. Do not hold the framework in the extension area only.
    • 8. Inspect for smoothness, continuity, and void. 9. Trim these excessive impression material exactly at the metal finish line on the tissue surface.
  15. Cast alteration
    • 1. remove edentulous area from master cast 1-2mm from tooth-tissue junction
    • 2. seat framework
    • 3. secure w sticky wax
    • 4. confirm nothing stone touching impression
    • 5. place retention grooves to hold altered areas
    • 6. bead and box ready to pour vaccum-mixed stone
  16. Materials for altered cast impression
    • Rubber base or metallic paste (ZOE) can be used.
    • Do not use ZOE for tissues with gross undercuts
Card Set
RPD2 3
RPD2 3